Roots vacuum pump is a rotary volumetric vacuum pump. Its structure is evolved from a Roots blower. First appearing in Germany in 1944, it was used as a mechanical booster pump to accommodate vacuum melting systems with large pumping speeds in the 10-1000 Pa pressure range. According to Roots vacuum pump working pressure range is divided into straight row of atmospheric vacuum Roots pump; vacuum Roots pump (mechanical booster pump) and high vacuum multistage Roots pump. The largest amount of domestic vacuum Roots pump. Roots vacuum pump compared with other oil-sealed vacuum pumps have the following characteristics: (1) a wide range of pressure in a larger pumping speed; (2) the rotor has a good geometric symmetry, so the vibration is small, stable operation. The rotor and the gap between the rotor and the shell, no lubrication, friction loss is small, can greatly reduce the drive power, which can achieve high speed; (3) no need to seal and lubricate the pump chamber can reduce the oil vapor on Vacuum system pollution; (4) pump cavity without compression, no exhaust valve. The structure is simple and compact, insensitive to the dust and water vapor in the gas being drawn; (5) the compression ratio is relatively low, and the hydrogen pumping effect is poor; (6) the surface of the rotor is a curve cylinder with a complicated shape, and the machining and inspection comparison difficult. Roots vacuum pump in recent years at home and abroad to get faster development. In smelting, petrochemicals, electrician, electronics and other industries have been widely used.
Elevator Door Modernization
Elevator Door Modernization, Elevator Door System Modernization, Elevator Complete Door Modernization, Elevator Complete Door System Modernization
Neglecting elevator door equipment jeopardizes riding public safety and increases owner liability. Modernizing elevator door equipment is important in making an older elevator system more reliable, safe, code compliant, efficient, and provides a more marketable appearance. This is particularly true with door operators. Door operators undergo tremendous wear and tear in daily operation. Each time the elevator stops, the door operators are activated at least two times, more frequently if occupants manually hold the doors open. Some elevator maintenance companies report that nearly 75 percent of their service calls are for malfunctioning door operators
Elevator Door Modernization, Elevator Door System Modernization, Elevator Complete Door Modernization, Elevator Complete Door System Modernization
CEP Elevator Products ( China ) Co., Ltd. , https://www.zjsmartcommercialescalators.com
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